How do scientists distinguish between magma and lava?

Scientists distinguish between magma and lava based on their location. Magma is molten rock found beneath the Earth's surface, originating in the upper mantle at depths of 70 to 200 kilometers. Lava, on the other hand, is molten rock that has erupted onto the Earth's surface from a volcano.12

Magma is less dense than the surrounding solid rock, causing it to rise towards the surface. It can collect in underground reservoirs called magma chambers before erupting as lava. The composition of magma influences its properties, such as viscosity and temperature, which in turn affect the behavior of lava flows. Lava flows can be fluid, like pahoehoe, or more viscous, like aa.213